Metering and dispensing systems are generally used to provide a measured flow of flowable material from a material reservoir to a particular application. Materials can include fluids, such as sealants, adhesives, epoxies, and the like. Metering and dispensing devices ensure that a specified amount of material is delivered to the application each time the material is required. For example, many operations in the manufacture of an automobile require an application of precisely metered materials, such as the application of sealants to an automobile's body structure. Metering and dispensing devices can be used to eliminate the guesswork, human error, and waste associated with having to apply a precise amount of material.
Such systems are commonly used to provide a uniform continuous flow, and also to provide a single application of a specific amount of material, often referred to as a metered shot of material. Metering and dispensing devices are commonly used to dispense sealants, adhesives, epoxies, and the like, including two-part materials. For example, a metering and dispensing system may dispense a two-part epoxy, where the system mixes a resin with a catalyst just before applying the two-part epoxy to an application. In such an application, it is often important to prevent weak spots, where the mixture is light on either the catalyst or the resin. To prevent such weak spots, metering and dispensing systems must ensure that both the catalyst and the resin are provided evenly and continuously.